IQ scores have u = 100 and o = 15. The distribution is normal. A new drug is touted as having the effect of raising IQ by 10 points and we recruit a sample of n = 36 people to test it on. Using a=.05, how much power will we have? Please show work.

What is the probability of randomly selecting a red haired person from this distribution below?

Grey Brown Blonde Black Red
Eyes Blue 2 14 6 11 9
Green 4 17 8 9 8
Brown 6 19 9 28 9

Using the above chart what is the probability of selecting a blue eyed blond from this distribution?

Given that the probability that Nancy will wear blue to class is 20% and the probability that Tim will wear blue to class is 30%. What is the probability that they will both wear blue to class on same day?

What is probability that one of them will wear blue to class?

I am having difficulty with my formula's. I am taking an online class and cannot get it right. Just need some guidance.

Solution Preview

1.

Power is the probability of rejecting the null hypothesis given that the alternative hypothesis is true. Let's first set up our two hypotheses:

H_0: u = 100
H_1: u > 100

The first step is to find the rejection region. Given that a = 0.05, we want the probability of falling into the rejection region to be 0.05, assuming the null hypothesis is true. For a one-tailed normal distribution, a = 0.05 corresponds to a z value of 1.645. Thus, we want to solve for X ...

Solution Summary

The probability of randomly selecting a red haired person form this distribution is given. The probability that one of them will wear blue to class is given.

1. The following are marks obtained by a group of 40 students on an English examination:
42 88 37 75 98 93 73 62
96 80 52 76 66 54 73 69
83 62 53 79 69 56 81 75
52 65 49 80 67 59 88 80
44 71 7

Help with this problem please:
Jane is told that her GMAT score is in the top 2% in her region at 28. The average score was 18. Tom scores 25 and Sandra scores 17. What are Jane, Tom, and Sandra's percentile scores?

1. For a sample selected from a population with a mean of µ=50 and a standard deviation of σ = 10:
a. What is the expected value of M and the standard error of M for a sample of n=4 scores?
b. What is the expected value of M and the standard error of M for a sample of n = 25 scores?
2. A population has a mean of µ

Suppose we have a population of scores with a mean (mu) of 200 and a standard deviation (sigma) of 10. Assume that the distribution is normal. Provide answers to the following questions:
1. What score would cut off the top 5 percent of scores?
2. What score would cut off the bottom 5 percent of scores?
3. What scor

A. Assuming that the distribution of IQ is accurately represented by the bell curve in Figure 5.16, determine the proportion of people with IQs in each of the five cognitive classes defined by Herrnstein and Murray.
Figure 5.16
The distribution of IQ (See the attachment)
b. Although the cognitive classes above are defined

1. Briefly define each of the following:
a. Distribution of sample means
b. Expected value of M
c. Standard error of M
2. For a sample selected from a population with a mean of µ=50 and a standard deviation of s= 10:
a. What is expected value of M and the standard error of M for a sample of n = 4 scores?
b. What is the

1. Place the following scores in a frequency distribution table. Include columns for proportion (p) and percentage (%) in your table. The scores are: 4, 6, 2, 9, 8, 8, 5, 7, 7, 3, 6, 6, 7, 4, 5, 8, 6, 5
2. Under what circumstances should you use a grouped frequency distribution instead of a regular frequency distribution?

Please answer the following question:
- Explain thoroughly, the concept of standard deviation.
- How does range affect standard deviation?
- What is a z-score, and how do z-scores relate to the mean of a set of data?
- Generally speaking, how is the percentage of data which lies in between two z-scores calculated?